N.Korea data hint at reactor’s restart

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WASHINGTON — A recent satellite image appeared to show North Korea is restarting a plutonium reactor, in a move that could raise renewed international alarm because of its nuclear weapons program, a US research institute said Wednesday.

The 5 megawatt reactor at the Nyongbyon nuclear facility was shuttered in 2007 under the terms of a disarmament agreement. Pyongyang announced plans in April to restart it amid a litany of threats toward the United States and South Korea after it faced tougher international censure because of its latest nuclear and rocket tests.

North Korea has since toned down its rhetoric and stepped up diplomacy with rival South Korea, but Wednesday’s finding by the US-Korea Institute at Johns Hopkins School of Advanced International Studies is a sign that the regime of Kim Jong Un is pressing ahead with its nuclear program.

Without access to the secretive facility, it is difficult to say with certainty that the reactor has restarted, but the institute said an Aug. 31 commercial satellite image showed white steam rising from a building next to the reactor. The building houses steam turbines and electric generators that are driven by heat generated by the reactor. The color and volume of the steam is consistent with the electrical generating system being readied to come online, indicating that the reactor is in or nearing operation, the institute said.

The analysis was written by Jeffrey Lewis and Nick Hansen, and provided to Associated Press ahead of publication on the institute’s website, 38 North.

When North Korea announced its plans in April, State Department spokeswoman Victoria Nuland told reporters that restarting the plutonium reactor would be ‘‘extremely alarming’’ but added: ‘‘There’s a long way to go between a stated intention and actually being able to pull it off.’’

There was no immediate comment from the department Wednesday on the new report. South Korea’s National Intelligence Service said it could not confirm the data because it involved confidential intelligence.

Commercial satellite images in recent months had indicated preparations for restarting the reactor were progressing rapidly. In June, the institute predicted the reactor could be up and running by the end of August, depending on the availability of fresh fuel rods to power it.

The reactor can be used both to generate electricity and produce fissile material for nuclear weapons, and once it is operating, can produce about 6 kilograms of plutonium a year — enough for one or two bombs.

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